Description of problem:
gpk-distro-upgrade: warning dialog doesn't close by close button.
When launch gpk-distro-upgrade from desktop icon, warning dialog appeared and that said "Cannot perform operating system upgrade". That is not a problem, but this dialog has close button but if I click it, dialog isn't closed.

Version-Release number of selected component (if applicable):
gnome-packagekit-2.91.5-2.fc15.x86_64

How reproducible:
always

Steps to Reproduce:
1.run gpk-distro-upgrade by desktop icon or gnome-terminal 
2.click close button

  
Actual results:
dialog is not closed.

Expected results:
dialog is closed.

Additional info:
I use live cd image which I download from following url: http://fedoraproject.org/wiki/Test_Day:2011-02-03_GNOME3_Alpha